From owner-cvs-all Sun Jan 26 23:10: 3 2003 Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D7C5E37B401; Sun, 26 Jan 2003 23:10:00 -0800 (PST) Received: from ns1.xcllnt.net (209-128-86-226.bayarea.net [209.128.86.226]) by mx1.FreeBSD.org (Postfix) with ESMTP id BD1EC43ED8; Sun, 26 Jan 2003 23:09:59 -0800 (PST) (envelope-from marcel@xcllnt.net) Received: from dhcp01.pn.xcllnt.net (dhcp01.pn.xcllnt.net [192.168.4.201]) by ns1.xcllnt.net (8.12.6/8.12.6) with ESMTP id h0R79xMW056797; Sun, 26 Jan 2003 23:09:59 -0800 (PST) (envelope-from marcel@piii.pn.xcllnt.net) Received: from dhcp01.pn.xcllnt.net (localhost [127.0.0.1]) by dhcp01.pn.xcllnt.net (8.12.6/8.12.6) with ESMTP id h0R79xXC002500; Sun, 26 Jan 2003 23:09:59 -0800 (PST) (envelope-from marcel@dhcp01.pn.xcllnt.net) Received: (from marcel@localhost) by dhcp01.pn.xcllnt.net (8.12.6/8.12.6/Submit) id h0R79wNg002499; Sun, 26 Jan 2003 23:09:58 -0800 (PST) (envelope-from marcel) Date: Sun, 26 Jan 2003 23:09:58 -0800 From: Marcel Moolenaar To: phk@FreeBSD.org Cc: Nate Lawson , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sbin/disklabel disklabel.c Message-ID: <20030127070958.GA2431@dhcp01.pn.xcllnt.net> References: <15853.1043649348@critter.freebsd.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15853.1043649348@critter.freebsd.dk> User-Agent: Mutt/1.5.3i Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, Jan 27, 2003 at 07:35:48AM +0100, phk@FreeBSD.org wrote: > In message , Nate Lawson wri > tes: > >On Sun, 26 Jan 2003 phk@freebsd.org wrote: > >> Robert Watson writes: > >> >We've always had a problem with ioctl's operating on storage devices > >> >regardless of the open mode (and permitted access modes) for the devidce > >> >nodes. > >> > >> And it ain't going to get any better as we get more weird "disks" > >> in the GEOM framwork. > > > >I'm not sure why boot block/disk label writes can't be done as ordinary > >writes and semantic checking performed by whichever GEOM layer thinks it > >knows best about that portion of a disk. What is wrong with that > >approach? > > It doesn't work without running a lot of special-case testing code, > possibly several times, on each and every disk I/O request. > > Considering how often people update their bootblocks, this would be > a totally unacceptable tradeoff. One of the thoughts I have on the issue is to have the geom classes have device nodes as side-entrances, independent of the producer- consumer interfaces. Direct access to the device nodes can then easily be checked with each read or write without pessimizing the P/C layering. The ioctl interface not not suited for GPT as the amount of data that has to be read or written is not fixed, as are the LBAs at which the data has to be written. -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message